- The document discusses the Fontan procedure for univentricular heart defects. It covers the evolution of the Fontan concept from the original atriopulmonary connection to lateral tunnel and extracardiac conduit techniques. It also discusses indications for Fontan, complications such as arrhythmias and ventricular dysfunction, and strategies to optimize outcomes like fenestration.

2. CONTENT OF DISCUSSION
• Introduction
• The ‘Fontan’ concept
• Indications for Fontan Operation
• Fontan physiology
• Evolution of Fontan Operation
• Fenestration
• Post Fontan Complications (Failing Fontan)
• Post-op follow up Outcomes
• Conclusion

3. Introduction
• “So in whatsoever creature there
is lungs, there is likewise in them
two ventricles of the heart, the
right and the left”
William Harvey (1628)

4. Introduction
• Normal mammal cardiovascular system
• Double—pulmonary and systemic—circuit, connected in series
• Powered by double pump—‘‘right’’ and ‘‘left’’ heart.
• Many Cardiac malformations ( prevalence approximately 1 per 3000
births) are characterised by only one functional ventricle.
• Fontan surgery is performed as the final staged operation not
amenable to biventricular repair.

7. Modifications of fontan
Original fontan 1971
Kreutzer 1973 Bjork1979
Kawashima 1983 Lateral tunnel
Extra cardiac condu

9. INDICATION FOR FONTAN
(UNIVENTRICULAR REPAIR)
Absence of two
adequate AV valves
• Tricuspid atresia /
Mitral atresia /
Hypoplastic left
heart
• AV canal defects
with atresia or
straddling of one
AV valve
Two adequate AV
valves with one
hypoplastic ventricle
• Double inlet LV /
RV
• Straddling of one
AV valve
Repair possible but
incomplete or
difficult
• Large / multiple /
non routable VSDs
• Miscellaneous
• PA with IVS
• Heterotaxy
syndromes

10. Ten Commandments
• AGE – 4 to 15 years
• NSR
• Normal SV Drainage
• Normal RA Volume
• Adequate PA size ( PA > 0.75 of Aorta)
• Mean PAP <15 mmHg
• PVR < 4 Woods units
• Normal LV Function
• Absence of pulmonary artery
distortion
• Competent AV Valve
Chousset et al 1977
Ideal candidate
1978, Choussat et al

11. Ten Commandments (or Four !)
• AGE – 4 to 15 years (>2 years)
• NSR (Atrial Pacing)
• Normal SV Drainage (Kawashima repair)
• Normal RA Volume (ECTC, RA plasty)
• Adequate PA size ( PA > 0.75 of Aorta)
• Mean PAP <15 mmHg
• PVR < 4 Woods units
• Normal LV Function
• Absence of pulmonary artery distortion
(PA plasty)
• Competent AV Valve (AV Valve repair)
Ideal candidate

12. • Only two significant risk factors for both early and late outcomes
• Preoperative ventricular function
• Preoperative pulmonary artery pressures >15 mmHg.
• Can be viewed as relative contraindications for Fontan

13. Fontan Physiology

14. Normal PhysiologyUniventricular HeartFontan Physiology
Marc Gewillig Heart 2005;91:839–846.

15. Fontan Circulation
• The systemic venous return enters the pulmonary
circulation, without an interposing ventricle, and
• All shunts at the venous, atrial, ventricular and
arterial level are interrupted
• Thus places the systemic and pulmonary circulations
in series driven by a SV
• post capillary energy - no longer wasted in systemic
veins, but collected and used to push blood through
lungs

16. • Advantages of a Fontan circuit :
– (near) normalisation of the arterial saturation
– abolishment of chronic volume overload on SV
• Cost for such circulation :
– Chronic systemic venous hypertension and congestion
– decreased cardiac output, both at rest and during
exercise
• Cardiac output - no longer determined by heart, but by
the transpulmonary flow (in turn regulated by PVR)

17. Fontan Circulation Hemodynamics
Caval venous pressure drives pulmonary blood flow
Fontan Paradox!!
Normal circulation:
Pulmonary artery pressure >15 mm of Hg, caval venous
pressures < 10 mm of Hg
Fontan circulation:
Caval venous pressure is > 10 mm Hg and pulmonary
artery pressure is less than 15 mm HG
Fontan circulation imposes caval hypertension and pulm arterial hypotension

18. Cardiac Output in Fontan
• No pulsatile pump to add forward energy to flow through lungs
• Flow return from the pulmonary vascular bed is thereby
restricted
• Decreased or absent preload reserve to the ventricle.
• Cardiac output (and thus preload) in a Fontan circulation at rest is
decreased to 70% (range 50–80%) of normal
Marc Gewillig et al. Interactive CardioVascular and Thoracic Surgery 10 (2010) 428–433

19. Determinants of Cardiac Output
Contractility
Heart Rate
Preload/Afterload

20. Role of Contractilty
• Does not Play significant role in Fontan Patients
• Except in Severe ventricular dysfunction
• In normal ventricular Function under filling is biggest
problem
Marc Gewillig et al. Interactive CardioVascular and Thoracic Surgery 10 (2010)

21. Role of Heart Rate
Plays
Negligible role
Tachycardia
does not
increase
cardiac output
Chronotropic
incompetence
AV synchrony
is important
Marc Gewillig et al. Interactive CardioVascular and Thoracic Surgery 10 (2010) 428–433

22. Role of Preload
• Most important determinant
• Determined by transpulmonary flow and
fenestration
• Transpulmonary flow determined by
– Transpulmonary gradient ( Venous pressure / LAP)
– Transpulmonary resistance (Fontan Resistance /
PVR)

23. Transpulmonary gradient
Systemic Venous
pressure in Fontan
Some degree of congestion
(Venous pressure >/= PAP)
Little variability at rest from
13 to 20 mm Hg
Mildly increased at exercise.
Pressures above 20 mmHg
are rarely seen
Determinants of
Left Atrial Pressure
AV Valve
Diastolic Function
AV synchrony
Fenestration
Marc Gewillig et al. Interactive CardioVascular and Thoracic Surgery 10 (2010) 428–433

24. Transpulmonary Resistance
• Fontan Connection Resistance
• Gradient across fontan circuit  poorly tolerated  Dec CO
• Causes:
• Stenosis
• Resistance offered by :- valves , conduits ,patches
• Flow dynamics and flow resistance
Laminarity of flow
Type of anastamosis
Marc Gewillig et al. Interactive CardioVascular and Thoracic Surgery 10 (2010) 428–433

25. Pulmonary Vascular Resistance
• Major determinant of cardiac output
• Drugs decreasing PVR improves cardiac
output
• Baseline PVR predicts future outcomes

26. Worsening PVR
Subotpimal PA growth
Absence of Pulsatile pulmonary flow
Functional Loss of Lung segments with ageing
Pulmonary lymphatic edema
Chronic use of Amiodarone
Living at High altitiude
Kreutzer et al Frontiers in Paediatrics December 2013

27. Evolution of Fontan concept

28. Atriopulmonary
Fontan and
Kreutzer
• First Generation
(1971)
Lateral Tunnel
Fontan
• Second
Generation
(1987)
The Extracardiac
Conduit Fontan
Procedure
• Third Generation
(1990)
Intra/Extracardiac
Conduit With
Fenestration
• Fourth
generation
(1987)

31. INTRA ATRIAL FONTANS

32. Advantage
Conduit enlarges as the child grows - may be used in
children as young as 1 year old
Decreased blood stasis and risk of thrombosis
Limited portion of RA exposed to high venous pressures
(reduces risk of arrhythmias)
Coronary sinus remains in low pressure atrium (allows
unimpended myocardial venous drainage)

34. EXTRA ATRIAL FONTANS

35. • Advantages :
– No or minimal CPB
– Entire atrium is left with low pressure - less atrial
distention, arrhythmia, and thrombosis.
– Avoids RA incisions and extensive atrial sutures
– Reduces risk of sinus node injury
– Reduces incidence of post op arrhythmias
• Disadvantages :
– Cannot enlarge as the child grows
– Performed only in child large enough to accept a graft of
adequate size to allow adult IVC blood flow.
– Risk of obstruction by thrombus formation or neo
intimal hyperplasia

36. Comparison
Atrio-pulmonary Lateral tunnel Extra cardiac
Growth + + -
Surgical
procedure
Open cardiac Open cardiac Closed
Atrial suture + ++ -
Atrial dilation/
arrhythmias
++ + +/-
SA nodal
dysfunction
+ + -
Thrombus
formation
++ - +
Laminar flow - + +

37. Fenestrated Fontan
• small opening or fenestration may be created between
the conduit and the right atrium
• Functions as a pop-off valve (a right-to-left shunt)
– prevent rapid volume overload to the lungs
– Limit caval pressure
– Increase preload to the systemic ventricle
– Increase cardiac output
• cyanosis may result from the right-to-left shunt

39. Harms Benefits
Source of Qs,
bypassing PVR
Increases preload
> CO
Limits or decrease
CVP rise acutely
Desaturation
Paradoxical
Embolization
Need to close
later

40. • Fenestration was performed selectively in 32 patients (39%),
including only 2 of the last 38 (5%).
• Prolonged (􏰃> 2 weeks) pleural drainage occurred in 13 patients, 8
with fenestration and 5 without.
• Fenestration is not necessary in most Fontan patients when an
extracardiac conduit technique is performed
• Should not be performed routinely
• Need for fenestration should be assessed after cardiopulmonary
bypass when hemodynamics can be evaluated accurately.

41. Fenestrate or Not ?
• Currently fenestration only in “high-risk” patients
• High PVR (>2 U/m2) or high mean PA pressure (>18 mm Hg)
• Distorted PAs secondary to previous shunt operations
• Poor systolic or diastolic ventricular function, with LV end-diastolic
pressure greater than 12 mm Hg or an ejection fraction less than
60%
• AV valve regurgitation
Lateral tunnel fontan
Fenestratiom
size
<12kg 4mm
12-30kg 5mm
>30kg 6mm

42. Whether and when to close ?
• Most of them close gradually and spontaneously (40 % 1)
• Delayed closure
• Benefits of increasing saturation translating in favorable
outcomes for body growth
• Optimal timing is unknown2
• Indication2
• Aortic saturation <90%
• Tolerance of BALLOON occlusion test

43. Procedure
• Evaluate arterial and venous collaterals
• About 15 to 20 min after the balloon occlusion, changes of
pressure and saturation within the Fontan circuit, left atrium and
aorta.
Criteria for fenestration closure is :
1. Right atrial pressure (Fontan Circuit) ≤ 18 mmHg
2. Increase in the difference of arteriovenous
oxygen saturation ≤ 33%,
3. Right atrial saturation (Fontan Circuit) ≥ 40%
4. < 30 % drop in Qs
5. Increase in the mean RA pressure <4 mmHg

44. Intra-Extra Cardiac conduit
with Fenestration
the internal orifice of the inferior vena cava

45. Intra-Extra Cardiac conduit
with Fenestration

47. How to achieve a Fontan Circuit
 At BIRTH, it is impossible to create a Fontan
circulation:
 PVR is elevated for several weeks
 SVC and IVC veins and pulmonary arteries may be too
small
 STAGED APPROACH  Adapt to changing
hemodynamics

48. How to achieve a Fontan Circuit
 Neonatal period (1 month)
 Improve the limited flow to the lungs – BT SHUNT / PA
BAND
 The infant is allowed to grow for several months
 Pulmonary vasculature will develop more
 PVR will stabilize
 PROBLEMS
 The heart will be subjected to chronic volume overload / pressure overload
 Ventricular function may deteriorate
 Expect mild progressive desaturation of the infant

49. How to achieve a Fontan Circuit
 At age 4-12 months
 The superior vena cava will be connected to the pulmonary
artery (Glenn)
 This will decrease the volume load to the heart
 The patient will remain cyanotic as the desaturated blood
from the IVC is still allowed to flow to the aorta

50. How to achieve a Fontan Circuit
 At 1-5 years of age
 The Fontan circuit is completed by connecting the IVC
to the pulmonary artery
Single Ventricle –
Bidirectional Glenn
Single Ventricle –
Completed Fontan
http://www.cincinnatichildrens.org/health/heart-encyclopedia/anomalies/sv.htm

51. FONTANS STAGING SUMMARY
 STAGE 1: AT 1 MONTH OF AGE
 OPTIMISE QP/QS :
 BT SHUNT / PA BAND
 STAGE 2: AT 4-12 MONTHS
 OPTIMISE VENTRICULAR VOLUME:
 BD GLENN / HEMI FONTAN
 STAGE 3: AT 1-5 YEARS
 REDUCE ADMIXTURE & DIRECT FUNCTIONAL
VENTRICLE TO SYSTEMIC CIRCUIT
 FONTANS

52. Fontan FAILURE
Fontan failure is defined as:
 NYHA functional class III or IV
 Death
 Fontan Take-down / Conversion
 Cardiac Transplantation

53. FONTAN COMPLICATIONS
ANATOMIC
LOCATION
COMPLICATION
Left ventricle Ventricular failure causing exercise
intolerance,ischemia and infarction
Pulmonary circulation Stenosis,dilatation or leakage of
anastomosis;pulmonary artery stenosis ;pulmonary
hypertension
IVC Increased pressures causing cirrhosis,liver failure and
portal hypertension;increased risk for liver carcinoma
RA with classic fontan
circulation
Dilatation(can be severe);poor turbulent flow;blood clot
formation
Collateral vessels and
shunts
Pulmonary AVM,aortopulmonary collateral vessels
Lymphatic system Protein losing enteropathy,plastic bronchitis, pericardial
and pleural effussion,chylothorax
Blood vessels Clot,emboli including pulmonary embolism

55. ventricular dysfunction

56. Arrhythmias
• includes sinus node dysfunction, predominant junctional
rhythm, atrioventricular block, supraventricular and
ventricular arrhyth- mias, and the risk of arrhythmic sudden
death.
• Sinus node dysfunction is reported in
• 40% of patients with atriopulmonary connections,
• 25% of lateral tunnel and extracardiac cavo-
pulmonary connection surgeries

57. Freedom from tachyarrhythmia
87.3%
61%

58. • Risk factors for the development of atrial tachycardia
include an
1. atriopulmonary connection,
2. preoperative bradycardia,
3. lack of sinus rhythm,
4. older age at Fontan and longer postoperative interval,
5. greater than mild atrioventricular valve regurgitation,
6. heterotaxy syndrome.

59. • Atrial reentrant tachycardia accounts for approximately
75% of supraventricular tachycardia, with focal atrial
tachycardia in up to 15% of patients.
• In lateral tunnel patients, the reentrant circuit may reside
in the pulmonary venous atrium.
• Atrial fibrillation is becoming increasingly common in
adult Fontan patients, and is present in almost half of
patients referred for Fontan conversion.

61. • Acute success rates from catheter ablation in the Fontan patient range from 40-75%,
with recurrence of tachycardia in 60% of patients during the first year.
• best suited for patients with lateral tunnel repairs and focal atrial tachycardia, or
atriopulmonary repairs who are not suitable candidates for Fontan arrhythmia surgery.
within 24e48 h from onset
lower success rates

62. Fontan Conversion

63. • Extra cardiac Conduit – IVC to PA
• Bidirectional Glenns Shunt – SVC to PA
• Resection of the diated Right Atrium
• Maze Procedure (Anti-arrythmic)
• Epicardial Pacemaker
Fontan Conversion

64. Fontans Complications
LYMPHATIC SYSTEM
 High venous pressure & impaired thoracic duct
drainage
 Lymphatic system dysfunction.
 Increased pulmonary lymphatic pressure  interstitial
pulmonary edema or lymphedema.
 Leakage into the thorax or pericardium 
PERICARDIAL AND PLEURAL EFFUSIONS (often
right-sided) and CHYLOTHORAX
 Rx – Reduce CVP , Fenestration , Fontan Conversion /
Take down

65. • Fu et al compared patients who underwent extracardiac
conduit Fontan procedure with and without a fenestration.
• The duration of pleural drainage with a fenestration was 10
days ± 􏰁 12 days, while without a fenestration the duration
was 13.2 days ± 􏰁 8.8 days (P 􏰁 .016).
Pleural effusion

66. Fontans Complications
LYMPHATIC SYSTEM
PROTEIN-LOSING ENTEROPATHY (5-15%%)
Time of presentaion - weeks to years after Fontan, mean ≈ 3.5 years
Its cause is unclear
 Elevated systemic venous pressure  Elevated hepatic
and portal venous pressure  Loss of enteric protein
 Interstinal Lymphangiectasis  Loss of enteric
protein
Hypoproteinemia, Immunodeficiency, Hypocalcemia, And
Coagulopathy
Fatigue, Peripheral Edema, Pleural & Pericardial
Effusions,weight loss, Ascites,lalabsorption & Chronic Diarrhea.
Low serum albumin level & Increased fecal α1- antitrypsin levels

67. PLE
50% mortality at 5
yrs
Time from PLE
Diagnosis
Recent data from some centers show with treatment advances,
survival has improved to 88% and 72% after diagnosis at 5 and
10 years, respectively.

68. Treatment
Hemodynamic stabilization
Hemodynamic stabilization
Decompress atrium( fenestration)
Improve hemodynamics – vasodilators
Nutritional stabilization
Diet : Calories dense, high protein, rich in MCT, salt restricted
Maintain protein : Albumin +/- globulin infusion regularly
Supportive measures to avoid infections – antibiotic Px, vaccines
Judicious diuretic use, Fenestration / Fontan Conversion /
Cardiac Transplantation

69. Plastic Bronchitis
• Rare condition , Incidence 3- 4%
• Risk Factors – Same as PLE
• Formation of mucofibrinous bronchial casts resulting in marked airway
obstruction.
• Patients will often expectorate these casts or require removal by
bronchoscopy
• Life-threatening events may occur in up to 40 percent of affected patients
• Management – Same as PLE
• Proposed treatment options
• Inhaled or systemic steroid
• Aerosolized mucolytics
• Aerosolized fibrinolytics such as tissue plasminogen activator

70. Fontan Circulation Complications
BLOOD VESSELS
Predisposition to COAGULOPATHIES
Thrombosis is more likely in patients with low CO and
venous stasis
Increased incidence of coagulation factor abnormalities
because of Hepatic Congestion
 Protein C
 Protein S
 ATIII deficiency
Chronic cyanosis–induced Polycythemia
Leads to chronic / recurrent Pulmonary Embolism
Anticoagulation / Asprin Prophylaxis of all patients is
controversial

72. Thromboembolism
• Incidence varies from 6% to 25%.
• Bimodal Peak
• Risk Factor
• Supraventricular arrhythmias
• Right atrial dilation
• Artificial material used to construct the Fontan circuit
• Right atrial “smoke”
• Fenestrated Fontan circuit
• Protein C deficiency

73. • N = 111
• 2 years either ASA (5 mg/kg/day, no heparin phase) or warfarin
(started within 24 h of heparin lead-in; INR : 2.0 to 3.0)
• Overall freedom from thrombosis 2 years after Fontan surgery
was 19%, despite thrombosis prophylaxis
• 86 % ECTC , 60 % fenestrated
• No significant difference between ASA and heparin/warfarin as
primary thromboprophylaxis

74. Annual Follow up
Monitoring
Constitutional Symptoms Aerobic activity, Exercise Testing
Cardiac Hemodynamics CXR / ECHO / CT or MRI
Rhythm ECG/Holter
Pulmonary Saturation resting / Exertional
Hepatic LFT / USG liver
Gastrointestinal Stool alpha 1 anti-trypsin

75. CARDIAC TRANSPLANTATION
• Failing Fontan circulation can benefit from
orthotopic cardiac transplantation.
• The main indications for transplantation:
– Heart failure
– Intractable arrhythmias
– Protein-losing enteropathy
– Plastic bronchitis

76. Prognosis after Fontan

77. SEQUELAE OF FONTAN OPERATION
• Perioperative mortality : 3-5 % (< 2 % in recent data)
• Overall survival
– 5 yrs – 86%
– 10 yrs – 81%
– 15 yrs – 73%
• 10 yr survival (lateral tunnel) – 87%
• 10 yr survival (extracardiac) – 92.4%

78. • Independent predictors of mortality:
1. Pre-op high PA pressure
2. Severe infection in early post-op period
3. Early morbidities :
4. Pleural and pericardial effusion
5. Low cardiac output
6. Sinus node injury
7. Pulmonary and systemic venous obstruction

79. • Factors asso. with long term morbidity:
1. Progressive ventricular dysfunction
2. Systemic venous hypertension
3. RA distension (classical)
4. Thromboembolic episodes
5. Worsening cyanosis
6. Heterotaxy syndromes
7. Significant AV valve regurgitation
8. NYHA class III / IV (pre-op)
9. Elevated PA pressure (pre-op)

80. Survival
Improvement in Surgical Results over time frames
5 Year survival 78.5%
10 Year survival 71.4% Gentles et al JTCVS 1997
Postoperative 15- to 20-year survival rates
after Fontan procedure range from 60 to 85
percent

81. Survival has improved !
Yves d’Udekem et al Circulation 2007
Hospital Survivors
10-year survival 91 %
20-year survival 84 %
94 %
81 %

82. Kreutzer GO. Thirty-two years after total right heart bypass. J Thorac Cardiovasc Surg 2007
Longest lived patient, 39 yrs after
surgery, 8 years after conversion
Current age 57 years

83. Conclusion
• Offers only definitive surgical palliation for wide variety of
complex CHD with single dominant ventricle
• Fifth Decade Now , quest for Ideal fontan Continues
• Perioperative and early mortality has decreased markedly
over the past 4 decades.
• ICEC Fenestrated Fontan had shown early promising results
• Routine Fenestration and Anticoagulation is controversial
• Identification of ‘failing’ Fontan before development of
complications is essential to improve outcomes.
• Fontan Conversion remains hope for older fontan patients
IT’S DEFENITELY NOT THE END OF THE ROAD
MUCH HAS BEEN ACHIEVED, AND MORE HAS TO COME!

84. Recent Advances

85. Fontan completion without surgery
Fontan preparation

86. • 34 patients underwent Fontan preparation with BDCPC.
• Median age was 7.7 months (5 to 51)
• Median intensive care and hospital stay durations were 1
and 6 days
• None of the patients required inotropes, chest tube
insertion, or mechanical ventilation.
• Overall survival after BDCPC with Fontan preparation was
77%.
• Despite longer bypass and ischemic times, Fontan
preparation at time of BDCPC was feasible
• Excellent early dynamics, and echocardiographic and
clinical outcomes
Ann Thorac Surg 2011;91:566–73

87. Percutaneous insertion
Reversal of Fontan Paradox
Normalization of hemodynamics J Thorac Cardiovasc Surg. 2013 January

88. “Those who believe that one ventricle can drive blood
full of spirit into the body and the lungs likewise, are
heretics.
They forget that nature, being divine, never gave a
heart to any where there was no need ”
William Harvey

89. Thank You